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Shetland windfarm - Viking Energy


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I'm trying to get my head around what efficiency means.

VE talk about load factor when Myth Busting about 53% efficiency for Burradale, however in the same breath they talk about a Capacity Factor in the comparison of other types of generation.

They are two quite different calculations as I understand it.

So, if Burradale is 53% efficient when meeting demand, what is the percentage in terms of Capacity... just wanting to compare like with like because surely it is efficiency in terms of installed capacity that really matters (...when trying to predict the potential profits of a windfarm).

 

Ok, this is my understanding of efficiency or capacity factor.

 

Each machine has a nameplate capacity, that is it is rated at a certain output when it is running flat out. I don't know the capacity of the Burradale turbines offhand but the nameplate capacity of the VE turbines will be 3.5 MW. Now, if one of the VE turbines was to run at full 3.5 MW output for an entire year, it would have a capacity factor of 100%. How the 53% for Burradale is calculated is by taking the actual output over a year and comparing it to the maximum possible output.

 

 

What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

Edited by Ched
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AT, where's the survey results showing the opinions of every single person (say over 18) in Shetland?  When was such a survey?  YOU are clutching at straws and you know it.

 

Aaannd Unlinkedstudent demonstrates that she doesn't understand how polling works.

 

BTW, there was a poll of sorts of every Shetlander (of voting age at least) in the last Scottish election when Billy Fox stood against Tavish on an anti-windfarm ticket. He was defeated 2:1. Which neatly reflects (and validates) the results of the Shetland Times polls.

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What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

 

Aah, I think I follow you. Could you give me a link to where you found this definition of load factor, as it's a definition I've never seen. Demand has nothing to do with it.

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Aaannd Unlinkedstudent demonstrates that she doesn't understand how polling works.

 

BTW, there was a poll of sorts of every Shetlander (of voting age at least) in the last Scottish election when Billy Fox stood against Tavish on an anti-windfarm ticket. He was defeated 2:1. Which neatly reflects (and validates) the results of the Shetland Times polls.

 

And you do....?

 

1st;

Not every Shetlander of voting age took part in the last election.

 

2nd;

I am anti windfarm and I DID NOT vote for Billy Fox and, I DID NOT take part in the ST poll.

 

Your understanding seems to be that it is OK to manipulate any result to meet your own agenda.

 

You just cannot assume that a 'non-vote' is 'in favour' or that the non-voter 'couldn't care less'.

Edited by Colin
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What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

 

Aah, I think I follow you. Could you give me a link to where you found this definition of load factor, as it's a definition I've never seen. Demand has nothing to do with it.

 

 

1. Load Factor

 

http://www.jstor.org/stable/1809629

http://en.wikipedia.org/wiki/Load_factor_%28electrical%29

 

http://www.demandcharge.com/Web_Pages/Articles/Electrical_Load_Factor.html

 

http://electrical-engineering-portal.com/demand-factor-diversity-factor-utilization-factor-load-factor

 

2. Capacity Factor

 

http://en.wikipedia.org/wiki/Capacity_factor

 

http://www.eia.gov/tools/faqs/faq.cfm?id=187&t=3

 

http://blog.enerdynamics.com/2012/02/08/capacity-factor-a-key-determinant-of-the-value-of-a-power-plant/

 

 

Do your own search on both terms. Above are a few top links I got back when doing my search. My previous post was accurate. The calculation of load factor is dependent on demand or utilisation. Capacity factor on the other hand is the calculation that consider the maximum theoretical output of a generator.

 

These are different calculations so if you are confusing them then you are being mislead and you are storing up trouble by misunderstanding potential productivity (that's if you think these factors are interchangeable).

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AT, where's the survey results showing the opinions of every single person (say over 18) in Shetland?  When was such a survey?  YOU are clutching at straws and you know it.

 

Aaannd Unlinkedstudent demonstrates that she doesn't understand how polling works.

 

BTW, there was a poll of sorts of every Shetlander (of voting age at least) in the last Scottish election when Billy Fox stood against Tavish on an anti-windfarm ticket. He was defeated 2:1. Which neatly reflects (and validates) the results of the Shetland Times polls.

 

 

On the contrary, it demonstrates that YOU don't understand how surveys work ... and since when have people voted on local matters at national level?  Whilst the proposed windfarm is of importance, it is one of many issues of importance and you know (or should) that other factors are considered when voting on national issues.  I voted for Billy Fox.  Billy Fox is also my local councillor - no doubt if we did things your way, you'd be saying that he lost in local elections because the people of Shetland didn't vote for him when they couldn't - I'll hedge a bet that quite a few peeps in town and elsewhere would have voted for him if they were given that opportunity at the local elections.

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What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

 

Aah, I think I follow you. Could you give me a link to where you found this definition of load factor, as it's a definition I've never seen. Demand has nothing to do with it.

 

You might want to check back to page 117 and refresh your memory...

 

JGHR, on 03 Feb 2013 - 11:28 AM, said:

Quote

Quote

Are you talking about load factor or capacity factor? the two are different. Do you happen to know what the capacity factor for Burradale is over the period that they have had 5 turbines running?

 

AT said:

What's the difference?

 

JGHR said:

Well, that’s a good question and I’ll do my best to answer it. Load factor is the ratio of average generated power to actual maximum demand over a given period of time. Capacity factor is the ratio of average generated power to theoretical maximum output over a given period of time. Traditionally load factor was a measure of how efficiently a generator was being used(traditional generating plants run must efficiently at, or close to their rated load) and capacity factor is a measure of the generators ability or inability to deliver its full load over the time period. If Burradale has a load factor of 53% that means, to me at least, that its average power output over a given time period is 53% of the maximum power peak they have provided to the grid over the same time period. If Burradale has a capacity factor of 53% that means that its average power output is 53% of its theoretical maximum over the given time period.

I am really not sure why load factor would be of much relevance to windfarms, perhaps you can enlighten me?, or why a comparison between capacity factors for different types of generation could possibly be in any way useful, so I am curious why you would present either as a measure of Burradales supposed extraordinary efficiency.

So were you talking about load factor or capacity factor and do you happen to know the capacity factor of Burradale since they have had 5 turbines available?

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Along with Mr Egbert Mcwhirter I was also quite impressed with Mr Philip Andrews letter, not only his research on the efficiency of wind turbines but also when he pointed out the " sleight-of-hand financial arrangement involving grants, subsidies, inflated feed-in tariffs".

How ever his replies posted here leaves me wondering what more he expects of the indigenous population in the fight against this project?

Off course large numbers of people are for it, they envisage perhaps a chance of making money through the construction phase, hold some false belief that this will somehow save the planet and the human race or  are convinced this will be an economic saviour for these Isles, perhaps they believe all these things.

Also it is to be expected that an even larger number are completely indifferent to the project, perhaps not even interested in it in the begining, now after 8 years worth of hot air sprouted here and throughout the media  there eyes probably glaze over that bit quicker!.

That leaves the practicle and inquisitve minded people who see it for what it really is.....one big f***ing con.

Sustainable Shetland with there signifcant number of members have done everything possible that is available to them within the legal and democratic functions of this country , no violence or arrests yet as far as I am aware? all very dignified.

I am surprised that nobody has written to counter your letter - http://www.shetnews.co.uk/letters/7524-time-warp

 I wonder why ?

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http://www.publications.parliament.uk/pa/ld201314/ldhansrd/text/131106-0003.htm#1311072000052

 

Scoll down to Amendment 106.  Seems like the House of Lords don't like what the Scottish Government want to do regarding just steamrolling ahead and ignoring the rule of the law.

 

Amendment 106 refers to a proposal regarding the licence - the House of Lords have basically said you need a licence before you can build a power station/wind farm/electricity producing wotsits and the proposed amendment was withdrawn.

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I'm trying to get my head around what efficiency means.

VE talk about load factor when Myth Busting about 53% efficiency for Burradale, however in the same breath they talk about a Capacity Factor in the comparison of other types of generation.

They are two quite different calculations as I understand it.

So, if Burradale is 53% efficient when meeting demand, what is the percentage in terms of Capacity... just wanting to compare like with like because surely it is efficiency in terms of installed capacity that really matters (...when trying to predict the potential profits of a windfarm).

 

Ok, this is my understanding of efficiency or capacity factor.

 

Each machine has a nameplate capacity, that is it is rated at a certain output when it is running flat out. I don't know the capacity of the Burradale turbines offhand but the nameplate capacity of the VE turbines will be 3.5 MW. Now, if one of the VE turbines was to run at full 3.5 MW output for an entire year, it would have a capacity factor of 100%. How the 53% for Burradale is calculated is by taking the actual output over a year and comparing it to the maximum possible output.

 

 

What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

 

 

I would say confusing rather than misleading, and going back to the VE website, it's not exactly clear what they are talking about. They start off talking about capacity factor, then load-capacity factor and finish with load factor. I have e-mailed them asking for clarification.

 

I'll post the answer here when (if) I get it.

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What's confusing me is the fact that VE refer to a 53% load factor for Burradale - Load Factor being the ratio of actual output over a period of time, to peak load (demand). You are talking about Capacity Factor which is, as you say, the ratio of actual output over a period of time, to maximum possible output.

 

Misleading isn't it?

 

 

I would say confusing rather than misleading, and going back to the VE website, it's not exactly clear what they are talking about. They start off talking about capacity factor, then load-capacity factor and finish with load factor. I have e-mailed them asking for clarification.

 

I'll post the answer here when (if) I get it.

 

 

That will be interesting.

 

I also think Philip Andrews raises some very interesting points about wind speed (Lang Kames anemometer data) and turbine power curves. Looking at Burradale for evidence is interesting but not the right way persuade investors or the public that the VE project is going to be sufficiently productive.  A very small negative difference in efficiency will have huge financial implications.

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  • admin changed the title to Shetland windfarm - Viking Energy

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